JPH11182651A - Sound reducing structure, gear set, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the sound of impact of a gear train without greatly increasing manufacturing costs. SOLUTION: When a pin 12 placed on a gear G4a and a viscoelastic member 14 placed in an oblong hole 13 in a gear G4b are engaged to transmit power between them, the viscoelastic member 14 reduces an impact force transmitted from the pin 12. Therefore, the sound of impact is reduced when, e.g. an electromagnetic clutch is in the state of transmitting power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear set and a sound reduction structure used in an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art In recent years, the tendency to consider the environment has been increasing worldwide. Such momentum has spread to so-called OA equipment used in offices, and OA equipment is required to be energy-saving, to reduce emission of dust and ozone, to be quiet, and the like.

[0003] One of such demands can be dealt with tentatively by providing a sound insulation wall around the entire OA equipment to reduce the noise of the OA equipment. However, providing such a sound insulating wall is not preferable because it leads to an increase in manufacturing cost and increases the weight of the device.

[0004] In order to achieve noise reduction of OA equipment without using a sound insulation wall as a whole, it is necessary to identify the cause of noise and to eliminate the cause fundamentally.

[0005]

In an image processing apparatus such as a copying machine or a printer which is a part of OA equipment, for example, a motor and a paper feed roller are used to transmit power to a paper feed roller at a predetermined timing. A gear train is often used between the two.

Incidentally, a certain amount of play is provided between the gears in such a gear train in order to prevent a competition. However, when power is transmitted from the motor to the paper feed roller via the gear train, the paper feed timing is determined using an electromagnetic clutch provided near the paper feed roller. Here, when the electromagnetic clutch is in the driving force disconnected state, the motor to the electromagnetic clutch are rotating with a light load, but the paper feed roller is in contact with the paper on which an image is to be formed and the load is reduced. It is in a state where it has been applied.

[0007] When the electromagnetic clutch is brought into a driving force transmission state in order to start feeding from such a state, an impulsive sound is generated. The impulsive sound is generated when the impulsive force is transmitted to the gears in the gear train at the moment when the electromagnetic clutch is in the driving force transmitting state, thereby causing vibration at the meshing portion of the gear and the gear side surface. It is considered something. From the viewpoint of reducing the noise of the OA device, it is preferable to reduce or eliminate the impact sound.

As one measure for reducing or eliminating the impact noise, it is conceivable to control the electromagnetic clutch to gradually increase the attraction force and gradually rotate the driven side. However, according to this measure, in addition to an increase in manufacturing costs due to the addition of a control circuit, the electromagnetic clutch is forced to be in a so-called "half-clutch" state for a long time, thereby causing early wear and the like in facing of the electromagnetic clutch. There is a risk of being invited.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides an assembled gear, an image forming apparatus, and a sound reduction structure in which the impact noise of a gear train is reduced without significantly increasing the manufacturing cost. Aim.

[0010]

In order to achieve the above object, a sound reduction structure according to the present invention comprises a driving force source, a driving force transmitting mechanism, and a driven body to which the driving force is transmitted from the transmitting mechanism. A switching mechanism provided in the transmission mechanism for switching connection and disconnection of a driving force; and an elastic member or viscoelasticity provided between the driving force source and the switching mechanism and deformed by receiving the driving force. By using a member, when the switching mechanism connects the driving force, the switching mechanism is characterized by comprising a sound reducing unit configured to increase the transmission of the driving force in an inclined manner.

[0011]

According to the sound reducing structure of the present invention, the sound reducing means is provided between the driving force source and the switching mechanism, and includes an elastic member or a viscoelastic member which is deformed by receiving the driving force. By using this, when the switching mechanism performs the connection of the driving force, the transmission of the driving force is increased incliningly, so that the transmission of the driving force is instantaneous, for example. The impact between the transmission elements in the transmission mechanism can be reduced, thereby reducing the impact noise.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram of a right side of a copying machine 1 as an image forming apparatus as viewed obliquely from behind. In FIG. 1, the entire surface of the copying machine 1 (left side in the figure)
The trays 2a and 2b for storing paper are shown in a pulled-out state. On the right side of the copying machine 1, a manual feed plate 3 is provided at an upper portion, and below the manual feed plate 3, an upper paper feed transport door 4a is provided.
And a lower sheet feeding / conveying door 4b.

An upper sheet feeding / conveying door 4a and a lower sheet feeding / conveying door 4
A paper feed unit is arranged inside each of b. The paper transport unit is provided inside the copying machine
a, 2b, and has a function of feeding and conveying the paper in the tray. FIG. 2 shows an example of such a sheet feeding / conveying unit.

FIG. 2 is a perspective view showing the sheet feeding unit 5 stored in the upper sheet feeding door 4a. The paper feeding and transporting unit 5 has electromagnetic clutches 10 and 10. Electromagnetic clutches 10, 10 to which driving force from a motor is transmitted
Is set in a driving force transmission state at a predetermined timing, and rotates a sheet feeding roller (not shown) via a power transmission path including a gear (FIG. 3). By rotating the paper feed roller, tray 2
The paper in a and 2b (FIG. 1) is fed and conveyed to perform copying. At this time, the operation sound of the sheet feeding / conveying unit 5 propagates to the outside via the sheet feeding / conveying doors 4a and 4b, the trays 2a and 2b, or a gap therebetween.

FIG. 3 is a diagram showing a power transmission system from the motor to the electromagnetic clutch in the paper feeding and conveying unit 5. In FIG. 3, a motor M as a driving force source is fixed to a frame F. On the other hand, a gear train Gt composed of gears G1, G2, G3 and G4 meshed sequentially from the motor M side.
Are rotatably supported by the frame F via shafts S1, S2, S3, and S4, respectively. Further, the gear G4 is a set gear combining two gears,
One gear G4a meshes with the gear G3 and the other gear G4
b meshes with a gear G5 rotatably supported adjacent to the electromagnetic clutch 10. The electromagnetic clutch 10 and the gear train Gt constitute a transmission mechanism.

An electromagnetic clutch 10, which is a switching mechanism, is connected to a rotating shaft 11, and a cord 10a is supplied from a power source (not shown).
When the driving force is transmitted by the electric power supplied via the gears G1, the gear G5 and the rotating shaft 11 rotate integrally. A paper feed roller (not shown), which is a driven body, is attached to the end of the rotating shaft 11, and paper is fed from the trays 2 a and 2 b (FIG. 1) by the rotation of the rotating shaft 11.

Next, the gear set G4 will be described in detail. FIG. 4 is an exploded perspective view showing the assembled gear G4.
In FIG. 4, a left gear G4a, which is a driving gear, has two pins 12 planted in a direction parallel to the axis. On the other hand, the right gear G4b, which is a driven gear, has an elongated hole 13 at a position facing each pin 12. Gear set G4
When assembling, the pin 12 is arranged so as to abut one end of the elongated hole 13. A viscoelastic member 14 having a shape matching the shape is arranged in the remaining space in the long hole 13. FIG. 5 is a view of one elongated hole 13 and the viscoelastic member 14 as viewed from the front. In addition, the pin 12 forms a protrusion, and the viscoelastic member 14 forms an elastic member or a viscoelastic member.

The viscoelastic member 140 has a rubber hardness of 20 to 60 degrees (preferably 35 to 50 degrees) and is made of silicon rubber, silicon gel, or the like. An example of such a viscoelastic member is Elastage (registered trademark) marketed by Tosoh Corporation.

Next, the operation of this embodiment will be described. In FIG. 3, although the motor M is rotating, the load is hardly applied to the gear train Gt because the electromagnetic clutch 10 is in the driving force disconnected state. Here, when a sensor (not shown) detects the paper feeding timing, power is supplied from a power supply (not shown) via the cord 10a, and the electromagnetic clutch 10 changes from the driving force disconnection state to the driving force transmission state. I do. In such a case, the power of the motor M is instantaneously transmitted to a paper feed roller (not shown), and the paper is fed at just the right timing.

In FIG. 4, the pin 12 of the gear G4a rotates in the direction of the arrow in FIG. 4 by receiving the power from the motor M. However, when a load is applied to the gear G4b from the paper feed roller, the viscoelastic member 14 is impulsively applied in the rotational direction. The viscoelastic member 14 receives a part of the force and deforms, and transmits the remaining force to the gear G4b via the long hole 13. Therefore, after the electromagnetic clutch 10 enters the driving force transmission state, the transmission of power between the gears G4a and G4b is performed gradually in a short time. That is, by using the viscoelastic member 14,
The collision between the tooth surfaces of the gears in the gear train Gt can be reduced, unnecessary vibration can be suppressed, and the impact noise can be suppressed.

When the sound pressure of a copying machine incorporating the drive system including the set gears according to the present embodiment was measured from the outside in accordance with DINEN 27779, 71.2 d
A value of B was obtained. On the other hand, when the same measurement was performed after replacing the clutch with one that does not use the viscoelastic member 14,
A result of 8.6 dB was obtained. That is, the sound reduction effect in a state where the present embodiment is incorporated in a copying machine is as follows.
It was 2.6 dB.

According to the present embodiment, it is possible to reduce the impact noise at the time of operating the electromagnetic clutch, which has been difficult to eliminate in the past.
It can be low enough to be unrecognizable. According to the present embodiment, it is possible to provide an image forming apparatus that can contribute to a quiet and comfortable office environment.

FIG. 6 is a diagram showing the relationship between pins and slots in a modification. In the embodiment shown in FIGS. 3 and 4, the pin is disposed at a position in contact with one end of the elongated hole. On the other hand, in the modification of FIG.
Is arranged at the center of the elongated hole 113, and viscoelastic members 114 having the same shape are arranged on the left and right sides of the pin 112. According to this modification, even when the gear G4a (see FIG. 4) rotates in both directions to transmit power, the effect of reducing the impact noise is exerted based on the function of the viscoelastic member.

FIG. 7 is a perspective view similar to FIG. 4 showing a relationship between a rotating shaft and a gear according to the second embodiment. It should be noted that the second embodiment will be described focusing on differences from the embodiment shown in FIGS. 2 and 3, and detailed description of common parts will be omitted.

The second embodiment shown in FIG. 7 is substantially different from the first embodiment in that a projection constituting a part of the sound reducing means is not provided on one of the gears of the set gear. , Provided on the rotating shaft. More specifically, the rotating shaft 215 fixed at one end to the gear G4c indicated by the two-dotted line forms a rectangular plate-shaped projection 215a that protrudes in the other end in the radial direction. On the other hand, the gear G4d
A part of the outer periphery of the center hole 216 that engages with the rotation shaft 215,
Two opposed notches 216a are formed. A viscoelastic member 214 is arranged in each notch 216a.

As in the above-described embodiment, also in the present embodiment, the viscoelastic member 214 is deformed by receiving a part of the force transmitted by impact, and the remaining force is transmitted through the notch 216a. To the gear G4d. That is,
By using the viscoelastic member 214, it is possible to reduce the collision between the tooth surfaces of the gears in the gear train, suppress unnecessary vibration, and suppress the impact noise.

Although the present invention has been described with reference to the embodiments, it should be understood that the present invention should not be construed as being limited to the above embodiments, and that modifications and improvements can be made as appropriate. is there. For example, the drive system from the motor to the assembled gear may use a timing belt instead of the gear train.

[0028]

According to the sound reducing structure of the present invention, the sound reducing means is provided between the driving force source and the switching mechanism, and uses an elastic member or a viscoelastic member which is deformed by receiving the driving force. Thereby, when the switching mechanism performs the connection of the driving force, the transmission of the driving force is increased incliningly, so that, for example, compared to the case where the transmission of the driving force is performed instantaneously, The contact between the transmission elements in the transmission mechanism can be reduced, thereby reducing the impact sound.

[Brief description of the drawings]

FIG. 1 is a diagram of a right side of a copying machine 1 as an image forming apparatus as viewed obliquely from behind.

FIG. 2 is a perspective view showing a sheet feeding / conveying unit 5 stored in an upper sheet feeding / conveying door 4a.

FIG. 3 is a diagram illustrating a power transmission system from a motor to an electromagnetic clutch in the sheet feeding and conveying unit 5;

FIG. 4 is an exploded perspective view showing the assembled gear G4.

FIG. 5 is a view of one elongated hole 13 and a viscoelastic member 14 as viewed from the front.

FIG. 6 is a diagram showing a relationship between a pin and a long hole in a modified example.

FIG. 7 is a perspective view similar to FIG. 4, illustrating a relationship between a rotating shaft and a gear according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 5 Paper feed conveyance unit G4 Assembled gear 10 Electromagnetic clutch 12, 112 Pin 13, 113 Elongated hole 14, 114, 214 Viscoelastic member 215 Rotation shaft 215a Projection

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Sadatoshi Inoue 2970 Ishikawacho, Hachioji-shi, Tokyo Inside Konica Corporation

Claims (7)

[Claims] 1. A driving force source, a driving force transmission mechanism, a driven body to which driving force is transmitted from the transmission mechanism, and a switching mechanism provided in the transmission mechanism for switching between connection and disconnection of the driving force. By using an elastic member or a viscoelastic member that is provided between the driving force source and the switching mechanism and deforms by receiving the driving force, when the switching mechanism connects the driving force, A sound reduction structure comprising: a sound reduction unit configured to increase transmission of the driving force in a tilted manner. 2. The transmission mechanism comprises: a driving gear connected to the driving force source; and a driven gear connected to the driven body. The sound reducing unit includes a driving gear and a driven gear. A projection disposed on one side and an elastic member or a viscoelastic member disposed on the other side and adapted to engage with the projection and transmit power between the projection and the projection; The gear set using the sound reduction structure according to claim 1, wherein the elastic member or the viscoelastic member reduces the impact force transmitted from the protrusion. 3. An image forming apparatus using the gear set according to claim 2. 4. The image forming apparatus according to claim 3, wherein the image forming apparatus is an electrophotographic image forming apparatus. 5. The image forming apparatus according to claim 3, wherein the image forming apparatus is an inkjet type image forming apparatus. 6. The image forming apparatus according to claim 3, wherein said image forming apparatus is an image forming apparatus using a photosensitive material. 7. The transmission mechanism includes a rotating shaft and a gear disposed around the rotating shaft, wherein the sound reducing unit includes a protrusion disposed on one of the rotating shaft and the gear, An elastic member or a viscoelastic member that is disposed on the other side and engages with the protrusion to transmit power between the protrusion and the protrusion; The sound reduction structure according to claim 1, wherein an impact force transmitted from the protrusion is reduced.